Air intake device for water pumps



Apri] 29, 1952 R. w. MUERLE 2,594,793

AIR INTAKE DEVICE FOR WATER PUMPS Filed April a, 194e Patented Apr. 29, 1952 AIR INTAKE DEVICE FOR WATER PUMPS Richard W. Muerle, Springfield, Ill., assignor to Montgomery Ward & Co., Incorporated, Chicago, Ill., a corporation of Illinois Application April 8, 1946, Serial No. 660,554

2 Claims. (Cl. 18S-49) The present invention relates to an improved form of air intake device for use in connection with water pumps, particularly those of the type in which water is pumped either from the ground, river, lake or reservoir into a tank in which an air cushion is maintained above the water, for the purpose of providing pressure to force the water to a point at a higher elevation than the location of the tank.

Such devices are commonly used onfarms and in homes in outlying districts where there is no established water supply system, and usually comprise a well, and a mechanically or electrically operated pump which may be either of the centrifugal or of the reciprocating piston type.

For simplicity of explanation the present invention will be described primarily in connection with a reciprocating piston type of pump, although the invention is by no means to be limited thereto.

Because of the fact that the oxygen and nitrogen contained in air has considerable solubility in water, especially under pressure, it has been found that when water is forced into a tank with an air cushion above it, this air cushion gradually diminishes in volume by reason primarily of the oxygen and nitrogen of the air becoming dissolved in the water and passing out therewith. Eventually a condition is reached where there is an insuicient air cushion above the water to permit the proper functioning of the system.

Inasmuch as water is a substantially incompressible substance, it has been recognized as desirable to have the benet of an expansible fluid medium to apply pressure to the surface of the water in the tank, so as to force it to a point at a higher level, such as the various faucets and other water outlets in a house or other building. By reason of the fact that a gas, such as air, can be compressed to one-half of its volume by doubling the pressure thereon (Boyles law), it becomes evident that a gaseous cushion is a very desirable element of this type of water supply system.

If, however, the water cushion is substantially lost and the tank is practically iilled with water. difficulties arise. Usually these types of water systems are so arranged that the pump will be actuated whenever the pressure in the system falls below a certain predetermined level, which in usual household water systems is arbitrarily set at 20 pounds. Thus, if the pressuredrops to 20 pounds, the pump starts up and continues to pump water from its source into the storage tank, thereby raising the level therein. The air above the water in the tank will thereby be progressively compressed until a predetermined pressure is reached. This is usually between 40 and 50 pounds, at which time, by means of a suitable relay switch the pump is inactivated. Thereafter, when water is drawn from the system and the water level drops therein, the air expands until there is again a 20 pound pressure in the system, whereupon the pump starts up again.

By reason of the fact that the volume of the air decreases, due primarily to the solubility of the oxygen and nitrogen thereof, it has long been the custom to allow a small amount of air to be drawn into the system while the water is beingv pumped into the storage tank. Various devices have been utilized for that purpose, for example, those commonly known in this art as snifters, the latter usually consisting of a small check valve which is connected by means of an appropriate small tube to a control valve which is under the control of a float within the storage tank. Whenever the water in the storage tank risesV above a predetermined level, in other words, when the air cushion becomes too small, this oat will actuate the control valve which allows air to enter the small tube and hence allows it toilow through the check valve into the suction chamber of the pump. The check valve at the suction chamber is -so arranged that it will open whenever the pressure within the suction chamber is below atmospheric, but will close when the pressure is atmospheric or greater; therefore, when the float has opened the snifter control valve, a small amount of air is drawn into the suction chamber and, upon the compression stroke of the pump, is forced, together with the water in the said chamber, into the pipe leading to the storage tank. When, however, a sufficient air cushion has been established in the tank, the Weight of the iioat will keep the snifter valve closed. .v

While such a device has been found fairly satisfactory, it is subject to a number of diiflculties and inconveniences. In the rst place, it is necessary to iind some way of transferring the motion of the float to the outside of the tank, which involves various mechanical diiculties, particularly the maintenance of air-tight conditions. Moreover, the snifter control valve which often is not in use for many days, or weeks, is likely to become clogged or corroded in which A case it will fail to vrfunction with the result that no air is admitted to the tank so that eventually the system becomes water-logged. When this occurs it is necessary to disconnect the pump and to drain the Water out of the tank, and allow air to enter the same, so as to reestablish the desired air cushion.

The present invention, however, aims to avoid these diniculties by providing a means for admitting a small but accurately predetermined amount of air into the suction chamber of a water pump, the amount of air admitted being so proportioned as to supply the amount of eX- cess air necessitated by the solubility of the oxygen component thereof in the water.`

Accordingly, it is one of the objects of thepresent invention to supply an air intake control which comprises a micro-porous air metering device that is connected with the suction chamber' of the pump, which device may be readily and easily attached and as easily replaced when desired by those having little or no mechanical or technical background.

Another object. of the present invention is to provide an air metering device of low cost which in essence consists of a housing containing a plurality of graded air lters, at least one of which is of a predetermined but small and denite porosity, other filters being established ahead of it tokeep the actual lter from becoming plugged by dirt or dust floating in the air.

Other objects of the present invention will appear in connection with the further description and the accompanying drawings, in which:

Fig. l is a more or less diagrammatic drawing l showing such portions of a water supply system as are essential for the understanding of the present invention, illustrating a well or other source of water, the suction end of a reciprocating piston type of pump, and a Storage supply tank, as Well as the preferred form of the new air meteringV device shown attached to the suction chamber of the pump, most of Fig. 1 being in cross section;

Fig. .2 shows, on a somewhat enlarged scale, and in exploded form, the actual air metering device and its component parts, the same being shown in perspective and also partially in section;

Fig. 3 is a cross sectional view, also on an enlarged scale, of amodied form of the invention; and

Fig. 4 is a similar view of a still more simplified form of theV air metering device, which may be used for practicingV the present invention,

In Fig. l is shown one end of a typical reciprocating piston pump consisting of the pump housing 5 with the therewith connected suction line E at the bottom of which there is shown the usual intake or foot 'I provided with a check valve 8, this foot and valve being immersed in the source of water 9'. A suitable check valve I is also provided at the upper end of the suction line e. The suction chamber II is shown as leading to a cylinder I2 in which there reciprocates a suitable piston I3 mounted on a piston rod i3d which is operated by the usual means, which are not shown. The suction chamber II is also provided with an outlet check valve Ill which leads into a pressure dome I5 from which water pumped into said dome enters a discharge pipe I6 which leads to the storage tank I'I into the side of which it is threaded, as for instance into the boss I8. The storage tank I1 is provided with the usual bottom I9 and top or head 20, an

air cushion 2I, in the normal operation o f the apparatus, being provided between the water level 22 and the top 20. An outlet pipe 23 leads from the tank to the distributing system for 'the water.

At the right hand side of the suction chamber I I there is shown an extension 24 which is threaded into the chamber housing as at 25, an air tight relationship being secured between the extension -'l and the chamber housing by means of a suitable gasket 2. Threaded at 27 into extension 213 is the tapering end 28 of the housing 29 of a small check valve 36 which is normally kept in closed position by means of the spring 3l, but which is capable of opening whenever subatmospheric pressure conditions exist in the suc-r tion chamber Il, as 'for instance when the pump piston i3 is moved to the left to draw water from -v pipe S into saidchamber.

` It is this condition which is illustrated in Fig. l.

Screwed as at 32 to the exposed end of the housing 29 of the check valve 38 is the nipple 33 of a suitable housing 3G of the air metering device which constitutes the essence o-f the present invention.

This air metering device consists of the said housing Eil within which, adjacent the nipple 33, is provided an annular shoulder 35. Against this shoulder rests a suitable gasket or sealing member 35 which may, for instance, be made of rubber, synthetic rubber, neoprene or the like. Said gasket has a centrally disposed opening 3l. Seated against this gasket 36 is an orice member 38 which consists of a disc of metal provided with an extension 3e which extends into the opening 3'! of the-gasket. Extending completely through the member 38 and its extension 39, is an opening 4S. There then may be provided a spacing ring or gasket d I and resting againstY the latter is a micro-porous meteringv plug 42. By the term micro-porous it is intended to imply that 'the material, while practically solid inappearance, is nevertheless provided with a, percentage of extremely ne pores so that particles which would be ltered out thereby would be between say from .0005f to .001" in diameter. In otherword's, this meteringl element 42 will pass. a definite amount of air-by reason of its porosity, but will not pass any particles which are larger than one one-thousandth of an inch. Located ahead of the element 42 are a series, for instance three, of lters 43 e4 and 45, which are increasingly `coarser as to theirfporosity. For instance. the pores in filter 43 may be twice as large as those in the metering element 32; those in filter l -may be one and one-half times as large as those in filter 43, while the porosity of filter 45 may be two or three times that of the porosity of lter "i3, All these various parts of the air metering device are contained within thehousing 34, being inclose juxtaposition witheach other, and all pressed against the resilient sealing member or gasket 35 by means of `a retaining ring (i6, which latter is locked in place within the housing 3d by having the end thereof crimped inwardly at fil, thus retaining the entire device in assembled relationship.

The function of the lters 43,64 and 45 is to assure that no dust or other particulate matter is permitted to enter the metering element 42 as the permeability of the latter must be maintained as nearly as possible at a denite predetermined value. This, value is also in direct relationship with the size of the orice 40. The gasket 36 is madeannular in form and the orifice member 38 is; provided with the extension 3S to' make sure housing 48 which contains an annular sealing member 45 and a metering plug 5I) which may be of the same type as the micro-porous metering plug 42 described in connection with Figs. l and 2. The member 5i) is retained within the housing 43 by having the latter turned over or crimped as at 5I. The other end of the housing 48 is provided with an internally threaded nipple 52 to permit of its attachment to the exposed end of the check valve housing 29. While such a device will work satisfactorily in fairly clean surroundings, it is subject to eventual clogging by dust.

A still greater simplification is Shown in Fig. 4, where the metering plug housing is omitted and the entire metering device is constituted by a plug 53 of micro-porous material of the same type as used in the plug 42 and the plug 50. The plug 53 has a threaded socket 54 for attachment to the check valve housing 29. A gasket 55 is provided at the bottom of the socket 54 lto provide a tight seal with the end of the check valve housing when the plug is attached thereto.

Various materials may be employed for producing the micro-porous filtering elements of the present invention, as it is to be distinctly understood that the invention is not limited to the particular material subsequently herein described and employed in the preferred embodiment of the invention.

Thus, for example, the metering plugs 42, 55 and 53, and the filters 43, 44 and 45 may be made of a powdered metal composite, preferably that of a non-ferrous metal. These materials are made by what is now commonly known as powder metallurgy, which means that they are produced from finely powdered metals which have been formed under very high compression and then sintered to form coherent masses. Thus finely divided brass or copper metal may be placed in a mold and compressed under very high pressure into a coherent article. This article is then heated to a temperature which is close to the fusing point of the metal, as a result of which the individual particles thereof are caused to cohere to each other at their points of contact, thereby forming a strong coherent body. Such a body, however, will be porous unless extremely high pressures have been used. Manufacturers have now developed their techniques of compressing these metals to a point where they can produce a compressed sintered body of almost any desired degree of porosity and with almost anyA desired degree of fineness of pores. These pores can be made extremely ne; in fact so fine that particles above five one-thousandths of an inch will be kept from passing through the material. Other methods of producing these porous articles is to mix powdered metals with combustible material and then to compress the mixture, whereafter, during the sintering, the combustible material burns out. A somewhat more accurate control of porosity is thus made possible. A particular type of such material which is commercially available is known under the name of Oilite which is furnished in copper as well as brass or bronze. However, it can also be made of aluminum and even of iron. However, for the present purposes, iron is not 6... advisable because of its proneness to rusting and corrosion.

Metering plugs and lters made out of natural porous materials such as diatomaceous earth and various forms of silica or even porous grades of porcelain maybe substituted for the metallic lter elements more particularly herein described. y

In place of the powdered metal composites it is also possible to use completely inorganic materials such as filters made of sintered finely powdered glass or tiny glass beads. Another material which lends itself to the present construction is the type of unglazed porcelain filter used in Berkefeld filters, such as is sometimes used for ltering microbes out of fluids.

The operation of theapparatus lof the present invention is substantially as follows:

Whenever the piston I3 is moving to the left and is creating a suction in the suction chamber II, this will lift valves III and 8 and water will rise in the suction line 6 and enter the suction chamber. At the same time, as a result of the opening of the check valve 30, a certain amount of air will .be drawn from the circumambient atmosphere through the various filtering elements 45, 44 and 43, and the metering plug 42 (as shown in Figs. 1 and 2), or metering element 50 or 53 of Figs. 3 and 4, if either should be the one associated with the check valve 29. Upon the return stroke of the piston I3, valves 8 and I0 will close as will also check valve 29, but valve I4 will open, as a result of which the water and the air contained in the suction chamber I I will be expelled therefrom under pressure into the dome l5 from whence the water will then find its way through the pipe I6 into the pressure tank Il. The pressure dome I5 also contains a certain amount of an air cushion which, of course, is likewise maintained as a result of the intermittent drawing of air into the suction chamber I I through the filters and metering plug.

If for any reason the amount of air thus introduced into the pump system is too great, there will eventually be an accumulation of too great a head of air vin the tank, but this produces no great problem as a suitable discharge valve may be provided in the pressure tank, if desired above the water line, from which air may be blown either manually or under the automatic control of a suitable float; such air discharge devices or bleeders being commonly used in apparatus of this general type and hence require no description herein.

The air intake device constructed in accordance with the present invention is extremely simple, as it contains no moving parts other than the intake check valve 29 which itself is of simple construction and is preferably made of any noncorroding, non-ferrous metal, such as brass, bronze, aluminum, or the like, this valve being fully protected against the action of dust and dirt by reason of the air filters and metering plug, and will function almost indefinitely. The air lters will also continue to be operative for a long period of time. Moreover, whenever the device ceases to function effectively as a result of clogging, it can very easily be replaced without requiring mechanical skill by merely substituting a new one for the old one. The exact position of the air metering device relative to the suction chamber is, of course, not limited to the points shown in the drawing, and applicant reserves for himself such obvious modifications as may occur to those skilled in the art to which the present invention appertains.

Applicant claims:

1. An air-intake device adapted for connection with water pumps comprising a housing having an inlet and outlet opening, and, in the order named and extending from the outlet to the inlet opening: a perforated compressible sealingmember, a centrally perforated orice member, a. micro-porous air-metering member, and a series of more grossly porous air-filtering members; said members being confined in said housing and forced against said sealing-member by an annular retaining-ring held in the inlet opening by the inwardly crimped Wall of said housing.

2. An air-intake device adapted for connection with Water pumps comprising a housing having an inlet and an outlet opening, and in the order named, and extending from the outlet to the inlet opening: an annular compressible sealing member engaging an inwardly extending shoulder of said housing, an orifice member having a central passage and an extension thereof extending into the central space of said annular sealing member, a micro-porous air-metering member comprising a sintered powdered metal 8 composite, and a series of more grossly porous air-filtering members, said members being conned in said housing and forced against said sealing-member by an annular retaining-ring held in the inlet opening by the inwardly crimped Wall of said housing.

RICHARD W. MUEBLE.

REFERENCES CITED The following references are of record in the le of this patent:

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